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'u' lm 11 IN V EN TOR.' fa@ ATTRNEY United States Patent4 O CLOSURE SEALJohn W. Watson, Evanston, Ill., assignor to The IIydrorBlastCorporation, Chicago, Ill., a corporation of Illinois ApplicationFebruary 12, 1952, Serial No. 271,226

3 Claims. (Cl. 220-46) This 'invention relates to dewatering devices forgranular material and more particularly to the construction of thecasing and seal for a dewatering device to prevent the loss'of materialduring operation.

It has been proposed in the copending application of Roderick S.Webster, Serial No. 136,349, led December 3l, 1949, now Patent No.2,644,587, to dewater granular material such as sand by confining it ina casing having a perforated bottom closure and forcing water therefromby a gaseous medium under pressure.

This operation has been highly successful, but a difliculty has beenencountered in maintaining a proper seal between the bottom of thecasing and the closure to prevent material from leakingtherebetweenduring operation. Experience `has `shown that when granular materialsuch as sand is wet, it iiows very readily and even though the sealingsurfaces are carefully formed, granular material may accumulatetherebetween to leave openings through which the material can leak.

It is accordingly one of the objects of the present nvention to providea dewatering device for granular material in which an effective seal isproduced between the casing bottom and the closure to prevent leakage ofgranular material therebetween during operation.

Another object is to provide a dewatering device in which the sealbetween the casing bottom and the closure is self cleaning to insureproper sealing therebetween regardless of accumulations of granularmaterial on the surfaces. Y

Still another object is to provide a dewatering device in which the sealis formed by an annular elastic strip which is arranged to wipe over theclosure during closing movement thereon and again to wipe over theclosure when the casing is subjected to pressure thereby to insure agood seal.

A further object is to provide a dewatering device in `which the sealingstrip is easily and securelymounted in the casing by means of anexpansible ring.

The above and other objects and advantages of the invention will be morereadily apparent when read in connection with the accompanying drawingsin which:

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. perforated closure shownas comprising an outer annular Figure l is apartial section through the bottom part i of a dewatering deviceembodying the inventionshowing the closure in open position;

Figure 2 is a view similar to Figure 1 showing the position of the partswith the closure closed but no pressure in thev casing; and

Figure 3 is a view similar to Figure 2 showing the position of the partswith pressure in the casing;

The apparatus as illustrated comprises a casing or container 10 ofvertical tubular form and which preferably has a smooth innercylindrical surface to receive wet granular material which is to bedewatered. At its lower end the outer surface of the casing is bevelledas indicated ,'at 11 so that the casing terminates in a relatively sharpedge and so that its inner surface continues as a smooth cylindercompletely to the bottom thereof.

The bottom of the casing is adapted to be closed by a ring 12 open inits center and supporting a screen 13 in its center portion. The ring 12is of such a diameter and width that it will seat on the lower edge ofthe casing and will project radially both inwardly and outwardly beyondthe casing edge with the screen 13 lying only inthe central part of thecasing bottom.

ln order to effect a tight seal between the closure and the casing,there is provided according to the present invention an annular strip 14of elastic material such as rubber which is normally of a` slightlysmallerv diameter than the casing interior. The strip 14 is secured inthe lower end of the casing above the bottom thereof by the annularexpansible ring 15, whose ends are connected by an adjustable reverselythreaded screw 16 sov that the `diameter of the ring can be varied. Tomount the seal, the ring 15 is slipped intoA one end of the annularstrip 14 and the assembly is then Vinserted in the bottom of the casingto a point such that the lower edge of the ring will be spaced above thecasing bottom as shown. The ring is then expanded by turning the screw16 to press the sealing strip tightly against the casing inner wall toeffect a tight seal therebetween and to hold the sealing strip and thering in place in the casing by friction. When so mounted, the lower edgeof the sealing strip 14 curves inwardly and downwardly as shown inFigure 1 to a point normally below the bottom edge of the casing.

When the closure is moved to its closed position as illustrated inFigure 2, the lower edge of the sealing strip 14 will engage the closurering 12 and as the closure moves toward the casing the sealing stripwill be bent upward so that its lower edge will wipe radially inwardover the closure. Thus, any granular material left on the closure willbe wiped therefrom under the edge of the sealingstrip to leave a cleansurface against which the strip can seal. The relatively sharp loweredge of the casing 10 produced by the bevel 11 will bite through andspread any accumulations of granular material between it and the closureto enable movement of the closure into firm engagement with the casingbottom.

When pressure is applied to the interior of the casing to force waterfrom the granular material therein, the iiexible sealing strip 14 willbe stretched and expanded to the position shown in Figure 3. During thismovement the inner lower edge of the strip will wipe radially outwardacross the closure to wipe out any granular material therebetween sothat a good sealing contact will be obtained. As finally expanded, thesealing strip will consist of two substantially right angular portionsone of which lies ilat against the inner surface of the casing and theother of which lies at against the closure. In this way a tight seal isformed between the casing and the closure which will prevent loss of anymaterial therebetween, even when subjected to relatively high pressureand with the granular'material in an extremely wet and ilowablecondition.

While one embodiment of the invention has been shown and described indetail, it will be understood that it is illustrative only and is not tobe taken as a definition of the scope of the invention, reference beinghad for this purpose to the appended claims.

What is claimed is:

1. A dewatering device for granular material comprising a verticalcasing open at its bottom and having a smooth cylindrical 4innersurface, the bottom of the casing terminating in a tapering relativelysharp edge, a ilat closure for the bottom of the casing movable againstsaid edge and a tubular strip of elastic material secured to the innerwall of the casing above the bottom thereof and normally extendingdownward and inward from its line of attachment to a level below thecasing bottom to t 4 engage and-wipefradially inward over the closurewhen it diameter than the casing fitting in the casing an exis`movedintoengagement with. saidedge. pansiblea-ring. ttingtrwithn. the.stu-ip. and. means` to. expandv 2. A dewatering device fongranularmaterial compristhe ring to cause it to prees the strip against theinner ing a vertical casing` open at itstbottom and having a casing wallat a level above the bottom of the casing, smooth cylindricaliinnersurface,`Y the bottom of' thel 5 the strip being of a width toproject radially inward and easing terminating ina'l taneri'ngfrelatively -sharp edge, a downward from the ring to a level below thebottom of the a-t closurefor thebottom of the casing movable againstcasing.

said*- edge, andf aA tubular-strip of elastic;` material Secured"totheinnerwall ofthe casing above the bottom thereof'- Refel'encesCfediin tha-51@ 0f this Ptet andnormally extending' downward and inwardffrom its- 10 UNIIEDA., STATES, BATENIS' line of attachment to a levelbelow the easing bottom to engage adwipe radially liWaIdovef'thve'clsure when it 1 lov. ismovedintoxengagementrwithsaid edge,pressure in: the 1628028, Ceu u e 'a l "MPL 10 1-927 casing stretchingthe strip into-.- engagement Withfthe lsl''s njvlHS-"Prul "1931 casing-IWalla-11dA causing' the loWe1-ed-g`ethereo'towpe- 15 1861537 L 1Vks aw-e *a I g'7 1932 radially out-WardOVeF thClOSliIef 1,870,973 Tehe me 91932 3f, A1 tewater-ing device for granular:materialV COUP 1975554 Mwa1ls n gi 2' 1934 prtising` aix/ernaarcasing-opener itebottom andhavnga- 231947 R-omssey bc 18 1941 smootbcl'yindricalinner-surface, the bottonrofjt'hecasingA 2%9'1'? 63" S1lb`"""``" Ae I' '4"1` terminating. in. atapering relatively sharp edge, a. "fiati 20 652%65 Lskirg' 'Jllllgs'135i closure. for the bottom of thev casmg movablegamsf 2,644,587Webster A 11115@ 7,J 1.953`

said edgeiy atubular elastic strig nomallyofsnaller

